Need to know biopsychology Flashcards
Neurotransmitters
- Any chemical that diffuses across neural synapse that binds to receptors on postsynaptic neuron
- causes changes in cells composition or behaviour
- chemical substances play important part in workings of nervous system by transmitting nerve impulses across a synapse
Cerebral cortex
- brains outer layer of grey matter
- made up of four main lobes
Four main lobes comprising the cerebral cortex
- Occipital lobe
- Parietal lobe
- Frontal lobe
- Temporal lobe
Frontal lobe functions
- reasoning
- Planning
- Parts of speech
- Movement
- Problem solving
- decision making
- Reading fluency
Parietal lobe functions
- Movement
- Orientation
- Recognition
- Perception of stimuli
Temporal lobe 3 functions
- Verbal Memory
- Speech
- Decoding/discriminating sounds
Occipital lobe function
-Visual processing
Motor area-
- located in frontal lobe
- responsible for voluntary movements by sending signals to muscles in body
- motor area on one side of brain controls muscles on opposite side.
Brocas area-
- Responsible for speech production
- found in left frontal lobe
Auditory area-
- located in temporal lobe
- responsible for analysing & processing acoustic info
- auditory area contains different parts
- primary auditory area involved in processing simple features of sound including loudness, tempo & pitch
- Info from left ear goes primarily to right hemisphere
- info from right ear goes primarily to left hemisphere
Visual area
- back of brain in occipital lobe is visual area
- receives/ processes visual info
- visual area contains different parts that process different types of info including colour shape/movement
- Info from right hand side visual field is processed in left hemisphere
- info from left hand side visual field is processed in right hemisphere
Somatosensory area
- Somatosensory area located in parietal lobe
- receives incoming sensory info from skin to produce sensations related to pressure pain temperature etc.
- Different parts of Somatosensory area receive messages from different locations of body
- somatosensory area on one side of brain receives sensory info from opposite side of body
Wernickes area -
- responsible for language comprehension
- found in left temporal lobe
Brain lateralisation
-Where a skill or function is preferably controlled by one side of brain over other causing hemispheres to have specialised functions
Norepinephrine function
- involved in flight or fight response activation of sympathetic nervous system
- acts to increase heart rate,blood pressure, trigger release of glucose & increase blood flow to skeletal muscles.
- both neurotransmitter,hormone aka as noradrenaline
Epinephrine function
- involved in flight or fight response activation of sympathetic nervous system
- works to regulate heart rate, blood pressure , air passage diameters & metabolic shifts
- both a neurotransmitter & hormone & is aka adrenaline
GABA (gamma aminobutyric acid) function
- regulates neuronal excitability, relieves anxiety/induces relaxation
- directly involved in regulation of muscle tone
- it’s most abundant inhibitory neurotransmitter in the mammalian central nervous system
Glycine
- acts as inhibitory neurotransmitter, most commonly in spinal cord, brain stem & retina
- when acting as a co-agonist with glutamate, glycine is an excitatory neurotransmitter
Beta endorphin function
- activates opioid receptors resulting in significant pain relief & relaxation particularly after physical trauma
- opioid drugs like morphine bind to opioid receptors & produce similar effects to beta-endorphin
Psychoactive drugs
- chemicals that cross blood brain barrier & alter brain chemistry & functioning
- these drugs lead to changes in perception, cognition, volition, mood or behaviour
Functions associated with medulla
- breathing
- heart rate
- blood pressure
Functions associated with pons
- bladder control
- eye movements
- facial expressions
- hearing
- posture
- respiration
- sleep
- swallowing
- taste
Glutamate function
- plays key role in growth and development of neurons
- highly involved in cognitive functions like learning and memory
- glutamate is most abundant excitatory neurotransmitter in vertebrate nervous system
Vasopressin function
- deals with neurological function like social bonding & memory
- commonly functions as a hormone where job is increase water retention in kidneys
Histamine function
- regulation of sleep and process of forgetting
- the cells that fire histamine are most active during wakefulness and slowest during sleep
- also involved in body’s inflammatory response but doesn’t act as a neurotransmitter in this capacity
Sleep wake cycle
- refers to alternating states of sleep and waking that are dependent on the 24hr circadian cycle
Circadian rhythm
-biological rhythms that occur over a 24hr period which is set and reset by environmental light levels
Ultradian rhythm
- cycles that last less than 24hrs like sleep stages that occur through the night
Infradian rhythms with example
- rhythms that have duration of over 24hrs and can be weekly, monthly or annually
- eg A monthly infradian rhythm is the female menstrual cycle, which is regulated by hormones that either promote ovulation or stimulate the uterus for fertilisation.
Divided attention
- brains ability to attend to two different stimuli at same time
- respond to multiple demands of your surroundings when you divide your attention the tasks efficiency will decrease
Interference
- when person has a hard time attending to two stimuli at a time we see interference when the brain is only able to process a certain amount of information
Dual task performance
- procedure that requires an individual to perform two tasks simultaneously in order to compare performance with single task conditions
Neurons 3 types
- sensory
- motor
- relay
Sensory neurons
- found in receptors such as eyes, ears, tongue and skin
- carry nerve impulses to the spinal cord and brain
- when these nerve impulses reach brain, they’re translated into ‘sensations’ such as vision, hearing, taste and touch
- but not all sensory neurons reach the brain as some neurons stop at spinal cord allowing for quick reflex actions
Relay neurons
- found between sensory input and motor output/response
- found in brain and spinal cord and allow sensory and motor neurons to communicate
Motor neurons
- found in central nervous system and control muscle movements
- when motor neurons are stimulated they release neurotransmitters that bind to receptors on muscles to trigger a response which lead to movement
- form synapses with muscles and control their contractions
Dendrites
- dendrites receive signals from other neurons or form sensory receptor cells.
- these are typically connected to the cell body, which is often referred to as the ‘control centre’ of the neurons as it contains the nucleus
Axons
- axon is a long slender fibre that carries nerve impulses in the form of an electrical signal known as action potential away from cell body towards the axon terminals where neuron ends.
Action potential
- neurons must transmit info both within the neuron and from one neuron to the next
- dendrites of neurons receive info from sensory receptors or other neurons
- this info is then passed down to the cell body and on to axon
- once info has arrived at axon it travels down its length in form of an electrical signal known as action potential
The reflex arc
- three types of neurons are arranged in circuits and networks the simplest of which is reflex arc
- In a simple reflex arc such as the knee jerk a stimulus is detected by a receptor cell which synapses with a sensory neuron
Sensory neuron and interneuron
- sensory neuron carries impulse from site of the stimulus to central nervous system the brain or spinal cord where it synapses with an interneuron
- the interneuron synapses with a motor neuron which carries the nerve impulse out to an effector such as a muscle which responds by contracting
Concordance rate
- measure of genetic similarity
- In a sample of for example 100 twin pies one twin of each pair has a phobic disorder.
- The number of times their other twin also shows the illness determines the concordance rate so if 40 have phobic disorder then the concordance rate is 40%
Gene
- part of the chromosome of an organism that carries info in the form of dna
Dopamine
- one of the key neurotransmitters in the brain with effects on motivation and ‘drive’
Noradrenaline
-neurotransmitter found mainly in areas of brain involved in governing autonomic nervous system activity eg blood pressure or heart rate
Autonomic nervous system
- governs brains involuntary activities
- eg stress heartbeat & it’s self regulating.
- divided into sympathetic branch & parasympathetic brain
Brain
- part of central nervous system that is responsible for coordinating sensation intellectual and nervous activity
Central nervous system
- comprises brain & spinal cord
- receives info form senses & controls behaviour & regulates physiological processes
- CNS receives info from sensory receptors in sense organs via sensory neurons & sends messages to muscles & glands via motor neurons
- simple reflexes relayed via spinal cord without brain involvement
-brain has 4 more areas;
.cerebellum left & right cerebral hemispheres,
cerebellum balance & coordination the diencephalon & brain stem regulates autonomic functions like breathing heart rate & swallowing
- cerebrum made up of right & left cerebral hemispheres connected by corpus callosum. have 4 lobes each which have specialist functions eg frontal lobe thought & speech production occipital lobe visual processing
- diencephalon made up of thalamus relay of impulses from sensory neurons & hypothalamus regulates body temperature & other homeostatic functions links to endocrine system via pituitary gland
Peripheral nervous system
- part of nervous system outside brain & spinal cord
- consists of all other nerves in body including somatic nervous system sensory neurons & motor neurons & autonomic nervous system which controls involuntary bodily functions like heartbeat & digestion
Somatic nervous system
-part of peripheral nervous system responsible for carrying sensory and motor info to and from central nervous system
Spinal cord
- bundle of nerves fibres enclosed within spinal column
- connects nearly all parts of the body with the brain
Synapse
- conjunction of the end of the axon of one neuron and the dendrite or cell body of another
Synaptic transmission
- refers to process by which a nerve impulse passes across synaptic cleft from one neuron the presynaptic to another the postsynaptic neuron
Endocrine glands
- special groups of cells within the endocrine system whose function is to produce and secrete hormones
Endocrine system
-network of glands throughout body that manufacture and secrete chemical messengers known as hormones
Hormones
- body’s chemical messengers.
- They travel through the bloodstream influencing many different processes
- including mood, the stress response and bonding between mother and newborn baby
Pituitary gland
- the ‘master gland’
- primary function is to influence the release of hormones from other glands
HPA axis
- describes sequence of bodily activity in response to stress that involves the hypothalamus pituitary and adrenal cortex
Localisation of function
- refers to belief that specific areas of brain are associated with specific cognitive processes
The biological approach to explaining Ocd
genetic explanations
COMT and SERT and diathesis
- COMT gene regulates dopamine production may contribute to OCD. A less active form of this gene is more common in OCD patients and produces higher dopamine levels.
- SERT gene may also contribute to OCD by reducing serotonin levels. A mutation of this gene been found in two unrelated families where six of the seven members had OCD
- diathesis stress each gene only creates a vulnerability (a diathesis) for OCD. Other factors such as childhood experience provide trigger (stress) for condition to develop
The biological approach to explaining Ocd Neural explanations High dopamine levels High doses of drugs The orbitofrontal cortex The worry circuit
- high dopamine levels and low serotonin levels are associated with ocd
- high doses of drugs that enhance dopamine levels induce stereotypical movements in rats whilst antidepressants drugs which increase serotonin activity reduce the symptoms of ocd.
- orbitofrontal cortex of frontal lobe and caudate nucleus part of basal ganglia are thought to be abnormal in people with ocd.
- Damage to caudate nucleus fails to suppress minor worry signals from ofc creating worry circuit
- worry circuit - serotonin plays key role in operation a of these structures and low serotonin level may cause them to malfunction.
- Dopamine is basal ganglias main neurotransmitter so high dopamine levels lead to overactivity of this region
The biological approach to explaining Ocd
Evaluation
-evidence for the genetic basis of ocd comes from family and twin studies
- nestadt et al found people
with first degree relative with ocd had a 5x greater chance of a lifetime risk of ocd themselves compared to risk levels in general population - meta analysis found identical twins were more than twice as likely to develop ocd if their twin has the disorder than non identical twins
- evidence supports genetic basis for ocd but concordance rates are never 100% so environmental factors must also play a role
The biological approach to explaining Ocd
Évaluation
Research support for genes and the role of ocd
- Menzies et al used to mri to produce images of brain activity in ocd patients and their immediate family members without ocd
- ocd patients and their close relatives had reduced grey matter in key regions of brain including ofc
- supports view inherited anatomical differences may lead to ocd in certain individuals in future brain scans may be used to detect ocd risk
The biological approach to explaining Ocd
Evaluation
Other disorders with genetic links to ocd
- research suggests ocd may be an expression of genes linked to other disorders like Tourette’s or autism and so would be a characteristic of a number of different disorders
- Pauls and leckman studied patients with Tourette’s syndrome and concluded ocd is one form of expression of same gene that determines Tourette’s. Obsessional and compulsive behaviour also found in children with autism and people with anorexia nervosa.
- supports view there aren’t specific genes unique to ocd but they merely act as a predisposing factor towards obsessive type behaviour
The biological approach to explaining Ocd
evaluation
Alternative psychological explanations
- two process model can be applied to ocd a neutral stimulus like dirt is associated with anxiety. Compulsive behaviours like hand washing maintain the association by negative reinforcement.
- exposure and response prevention is a similar treatment to sd patients experience their feared stimulus and are prevented from performing their compulsive behaviour
- albucher et al report that most adults with ocd improved considerably using erp suggesting that ocd has psychological as well as biological causes
CBT ellis model
Ellis REBT
- Ellis rational emotive behaviour therapy is type of cbt aims to turn irrational thoughts into rational thoughts and resolve emotional and behavioural problems
- Ellis model was expanded to ABCDEF D: disputing irrational thoughts and beliefs E: effects of disputing and effective attitude to life F: the new feelings that are produced
- REBT focuses on challenging or disputing irrational and self defeating thoughts and replacing them with effective rational beliefs. Logical disputing empirical disputing and pragmatic disputing can be used
- clients complete homework assignments as enables irrational beliefs to be tested against reality
- behavioural activation encourages clients to engage in pleasurable activities that they used to enjoy
- therapists provide clients with unconditional positive regard to convince clients of their value as humans. Another feature is for clients to be more active since being more active leads to rewards that are an antidote to depression
CBT ellis model
Ellis REBT
Évaluation
Research support for REBT
- ellis claimed 90% success rate for REBT in treatment of depression. In addition review by cuijpers et al of 75 studies found CBT was superior to no treatment
- however Ellis recognised therapy wasn’t always effective as some clients didn’t put their revises beliefs into action. Therapist competence also explains some of variation in CBT outcomes
- suggests REBT is effective but it’s effectiveness depends on client and therapist
CBT ellis model
Ellis REBT
Évaluation
Support for behavioural activation
- babyak et al randomly assigned people with depression to a course of aerobic exercise antidepressant drug treatment of both
- all three groups exhibited significant improvement after 4 months. exercise group had significantly lower relapse rates than medication group
- shows a change in physical activity can indeed be beneficial in treating depression
CBT ellis model
Ellis REBT
Évaluation alternative treatments are available
- most popular treatment for depression is use of antidepressants such as ssris.
- Drug therapies also require less effort by client than CBT
- drug treatment could enable depressed client to cope better with demand of cbt. review by cuijpers et al found cbt was especially effective if used in conjunction with drug therapy
- suggests using both cbt and drug therapies might be best option
CBT ellis model
Ellis REBT
Evaluation
All methods of treatment for mental disorder may be equally effective
- luborsky et al reviewed over 100 studies comparing different therapies
- found only small differences between them in terms of their effectiveness
- Sloane et al showed psychological therapies share many common factors such as being able to talk to a sympathetic person and express ones thoughts
- lack of difference between psychothérapies might be result of commonalities they share. known as the ‘dodo bird’ effect
Parasympathetic nervous system
- parasympathetic nervous system is concerned with rest & digest response.
- Acetylcholine is main neurotransmitter.
- slows heartbeat reduces blood pressure & restores diegative processes to normal.
Sympathetic nervous system
- sympathetic nervous system controls fight & flight emergency responses.
- Noradrenaline is main neurotransmitter it increases heart rate, dilates blood vessels & pupils slows down non-emergency processes like digestion
Neurotransmitter: serotonin
-inhibitory neurotransmitter involved in regulation of mood, sleep, appetite, and memory and is derived from the amino acid tryptophan
Endogenous pacemakers
What are they?
- biological clocks in brain controlling biological rhythms
- most likely the suprachiasmatic nucleus in the hypothalamus
Exogenous zeitgebers
What are they?
- external cues in environment may affect our biological rhythms
- eg influence of light on the sleep wake cycle
The suprachiasmatic nucleus
What is it?
- most important endogenous pacemaker lies in hypothalamus
- closely linked to pineal gland, both are influential in maintaining circadian sleep/wake cycle.
- SCN controls other biological rhythms, as it links to other areas of brain responsible for sleep & arousal.
- SCN also receives info about light levels from optic nerve, which sets circadian rhythm so that its in synchronisation with outside world, e.g. day & night.
The pineal gland
What is it and what does it do?
- an endogenous pacemaker works with SCN
- contains light sensitive cells
- when light is sensed melatonin production is inhibited
- when light level falls melatonin production increases
- induces sleep by inhibiting brain mechanisms that promote the awake state
- pineal gland and melatonin regulate sleep wake cycle
Animal studies support the role of endogenous pacemakers
Morgan and Blinkley
A03
Morgan
-hamsters have a SCN in their forebrain
- when removed their nocturnal patterns ceased
- when new fetal SCN cells were implanted they regained their circadian rhythm
- when fetal SCN cells of diurnal animals placed in nocturnal animals became diurnal
Blinkley
-studies chickens
- pair of pineal glands lie under the surface of a thin layer of skull at the top of the head
- gland responds to amount of light it receives
- decrease in light - increase in hormone melatonin
- explains regularity of cock crow because melatonin has decreased in response to light at dawn
Evaluation of exogenous zeitgebers
Campbell and Murphy study kneecaps
A03
Campbell and Murphy
- applied light to the back of the knees of human participants
- were able to shift the circadian rhythm in body temperature and melatonin production
- shows that light can reach the brain without passing through the eyes
A03 exogenous zeitgebers and endogenous pacemakers
Animal studies into the role of the SCN
Point
-SCN role in sleep wake cycle can be demonstrated with animals through lesion studies and cellular implantation
Explain
-DeCoursay destroyed SCN connections in 30 chipmunks
- returned them to natural habitat for 80dys.
- noted many of them were killed by predation not long after
- as they ventured out of their nests at wrong time of day,
- suggesting their normal sleep wake cycle had been impaired.
Elaborate
- strength-manipulation of SCN (IV) was conducted under controlled conditions so results can be replicated and show clear cause and effect relationship
ie damage/change to SCN alters sleep wake cycle. issues in generalising these findings to much higher order species like humans who also have many complex social cues which may alter sleep wake patterns.
study- considered unethical as rodents exposed to extreme harm: could be argued findings from this research do not justify means of obtaining them
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Reductionism:the role of peripheral oscillators
Point
- simplistic to suggest SCN is only endogenous pacemaker responsible for regulating sleep wake cycle
Explain
-research demonstrated there are many peripheral oscillators found in many other organs in body like adrenal gland, œsophagus, lungs, liver, pancreas and skin that not only function in combination with SCN they also have ability to work independently.
- Campbell and Murphy demonstrated light may be detected by skin receptor cells even when same info isnt received by eyes.
- 15 patients were woken at various times of night and light was shone onto back of knees.
- some cases researchers manger to alter sleep wake cycle of these participants by 3hrs.
- suggests light need not enter eyes & stimulate SCN in order to exert an effect on sleep wake cycle.
Elaborate- methodological limitations- other psychologists have suggested participants may have had some limited light exposure to eyes.
-only isolated light in this experiment & didn’t control for influence of other exogenous zeitgebers like time meals were taken & ambient temperature on sleep wake cycle
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Role of exogenous zeitgebers may be overstated
Point
- role of exogenous zeitgebers may have been exaggerated as evidence that although external environmental cues may vary
-some individuals pacemakers are set to withstand their influence
Explain
-case study by Miles of young man blind from birth with circadian rhythm of 24.9 hrs whose sleep wake cycle couldn’t be adjusted regardless to changes to social cues.
-He required medication to allow him to sleep and wake up every day at appropriate times.
Elaborate
- many psychologists argue this study is example of exceptional circumstance and for most people there’s interaction between our internal pacemaker and exogenous zeitgebers that sets our circadian rhythm.
-Isolating each factor and investigating each separately may tell us very little about how our circadian rhythms are set in real life
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Issues with case study evidence to support the role of endogenous pacemakers
Point
- most research looking at endogenous pacemakers and exogenous zeitgebers influence on sleep wake cycle is case study/studies using small samples like siffre cave study and aschoff and Wevers bunker study
Explain
- impossible to generalise results to whole populations of people as there may be some individual differences in research sample
-that makes these participants respond changes sleep/wake cycle in atypical ways eg siffre noted when he went into cave at 60yr his body responded very differently with his body clock following more of a 48hr cycle.
Elaborate
- suggests results can’t be generalised from small samples onto everyone as factors like age and gender may have significant impacts on our circadian rhythms.
A03 exogenous zeitgebers and endogenous pacemakers
Practical applications using light exposure to avoid jet lag
Point
- jet lag can be severe condition causing sleep appetite and mood disturbance.
- by understanding role exogenous zeitgebers have on sleep we can decrease impacts jet lag has on our sleep wake cycles
Explain
- burgess found exposure to bright light following an east west flight decreased time needed to readjust to local time on arrival.
- 3 groups of volunteers were exposed to either continuous bright light, intermittent bright light or dim light.
- found participants in continuous bright light group shifted their circadian rhythm back to 2.1 hrs intermittent bright light 1.5 hrs and dim light 0.6 hrs
Elaborate
- those in continuous bright light group felt sleepier 2 hours earlier in evening and woke up 2hrs earlier in morning closer to local time conditions they would find themselves in after and east west flight.
- research demonstrated we can entrain our circadian rhythms to fit into changing time zones to reduce impact of jet lag.
- has implications on economy as individuals who take long flights for business can improve productivity & concentration upon landing at destinations & get on with jobs more rapidly
Biological rhythms
What are they?
- biological rhythms are cyclical patterns within biological systems have evolved in response to environmental influences eg day and night
- 2 key factors that govern biological rhythms:endogenous pacemakers (internal) body’s biological clocks and exogenous zeitgebers (external) which are changes in environment.
- 3 biological rhythms: circadian, infradian, ultradian
Sleep wake cycle
- circadian clock located in SCN in hypothalamus of brain one in each brain hemisphere
- SCN is tiny pinhead sized area containing just 20,000 or so very small neurons
- but it has responsibility for sending signals to several other parts of brain to regulate daily sleep wake cycle, body temperature, hormone production and other functions
Sleep wake cycle and body temperature
- core temperature usually reaches minimum around 4:30 - 5:00 am in morning in human adults and melatonin (normally completely absent during daylight hours) typically begins to be produced
- 8:00 - 9:00pm at night
- stops around 7:00 -8:00am in morning
- deepest tendency to sleepiness occurs in middle of night around 2:00 -3:00am along with shorter and shallower period of sleepiness about 12hrs later around 2:00-3:00 pm in afternoon
Evaluating circadian rhythms
Research support siffre
- research been conducted to investigate circadian rhythms and effect of external cues like light on this system
- siffre found absence of external cues significantly altered his circadian rhythm
- when he returned from an underground stay with no clocks or light he believed date to be a month earlier than it was
- suggests his 24hr sleep wake cycle increased by lack of external cues making him believe one day was longer than it was and leading to his thinking that fewer days had passed
Evaluating circadian rhythms
Individual differences
Individual differences
- Duffy et al found morning people prefer to rise and go to bed early about 6am and 10pm
- whereas evening people prefer to wake and go to bed later about 10am and 1am
- shows there may be innate individual differences in circadian rhythms which suggests that researchers should focus on these differences during investigations
Evaluating circadian rhythms
Temperature may be more important than light in determining circadian rhythms
- buhr et al found fluctuations in temperature set timing of cells in body and caused tissues and organs to become active or inactive
- claimed info about light levels is transformed into neural messages that set body’s temperature
- body temperature fluctuates on a 24hour circadian rhythm and even small changes it can send a powerful signal to our body clocks
- shows circadian rhythms are controlled and affected by several different factors suggests more holistic approach to research might be preferable
Corpus callosum
Responsible for
-nerve fibres responsible for swift communication between the hemispheres
